If you mail in a paper return, take it to the post office (verify the last collection hours to ensure you get your return in the mail on time); do not leave it in your mailbox. To get the April 15 postmark, the deadline is 11:59 p.m. Monday.

Double check your math.

Be sure to enter Social Security numbers and names for all individuals on your tax return exactly as they appear on their Social Security cards.

Make sure to enter bank routing and account numbers correctly for direct deposit of your refund.

Remember to sign the return. E-filers will sign the return electronically using a Personal Identification Number.

Keep all tax documents in a safe and secure spot where they are out of sight